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bsj-2993
Acoustic and Thermal Insulation of Nanocomposites for Building Material: Improvement Of Sound And Thermal Insulation Properties Of Nanocomposite
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This work aims to enhance acoustic and thermal insulation properties for polymeric composite by adding nanoclay and rock wool as reinforcement materials with different rations. A polymer blend of (epoxy+ polyester) as matrix materials was used. The Hand lay-up technique was used to manufacture the castings. Epoxy and polyester were mixed at different weight ratios involving (50:50, 60:40, 70:30, 80:20, and 90:10) wt. % of (epoxy: polyester) wt. % respectively. Impact tests for optimum sample (OMR), caustic and thermal insulation tests were performed. Nano clay (Kaolinite) with ratios ( 5 and 7.5% ) wt.% , also hybrid reinforcement materials involving (Kaolite 5 & 7.5 % wt.% + 10% volume fraction of rockwool ) were added as reinforcement materials to the optimum sample. Results of impact test prove that the optimum sample has (80:20) wt. % of mixing ratio of (epoxy: polyester) wt. % for using as matrix materials. Moreover, the adding of nanoclay (Kaolinite) with ratio (7.5 wt.%) leads to the highest sound insulation. The sound intensity started at (99.8) db at 100 Hz, and reached to (101.3) db at 10000 Hz., which is much lower than the values obtained from the un-reinforced blend, of which the sound intensity started at (107.2) db and reached to (108.7) db., at the same range of frequencies. Thermal conductivity results show that the optimum matrix with (7.5 %) wt. % has the lowest value about (0.443 k.w\m .c).

        The results show that the blend reinforced with nano clay in a weight fraction (7.5)% has the best sound insulation, so that the sound intensity started at (99.8) db at 100 Hz., and reached (101.3) db at 10000 Hz., which is much lower than the values obtained from the unreinforced blend, of which the sound intensity started at (107.2) db and reached (108.7) db., applying the same range of frequencies. The same casting (blend+7.5% nanoclay) showed the lowest value of thermal conductivity (xxxx) W.m°C in comparison with castings that were made of unreinforced blend and those  hybridized with rockwool.

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Publication Date
Fri Sep 06 2024
Journal Name
Journal Of Optics
Optimization photodetection performance: investigation of doping effect on PVA/Y2O3 composite material
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In this work, the photodetection performance of polyvinyl alcohol (PVA) nanofibers and its composite with yttrium oxide (Y2O3) at different concentrations (2.5, 5, 10) wt% are examined deposited on p-type Si with (111) orientation. Electrospinning technique was used to create nanofiber composites. Adding Y2O3 significantly impacts the PVA nanofibers where ultraviolet-visible (UV-Vis) spectroscopy optical absorption energy gap decreases with increased concentration (2.8, 2.6, and 2.3) eV. X-ray diffraction was used to investigate crystal structure, which is cubic structure. The chemical composition study was conducted using Fourier transform infrared spectroscopy (FTIR) spectra, which revealed the stretching vibrations related to the Y-O bon

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Publication Date
Sat Feb 20 2010
Journal Name
Indian Journal Of Science And Technology
Investigation on picosecond laser ablation of dental material using FIB/SEM techniques
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Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
Vibration Control Analysis of a Smart Flexible Cantilever Beam Using Smart Material
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This paper features the modeling and design of a pole placement and output Feedback control technique for the Active Vibration Control (AVC) of a smart flexible cantilever beam for a Single Input Single Output (SISO) case. Measurements and actuation actions done by using patches of piezoelectric layer, it is bonded to the master structure as sensor/actuator at a certain position of the cantilever beam.
The smart structure is modeled based on the concept of piezoelectric theory, Bernoulli -Euler beam theory, using Finite Element Method (FEM) and the state space techniques. The number of modes is reduced using the controllability and observability grammians retaining the first three
dominant vibratory modes, and for the reduced syste

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Building a Reliable Steganography System Using Random Key in a spatial Domain of Image
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With time progress importance of hiding information become more and more and all steganography applications is like computer games between hiding and extracting data, or like thieves and police men always thieve hides from police men in different ways to keep him out of prison. The sender always hides information in new way in order not to be understood by the attackers and only the authorized receiver can open the hiding message. This paper explores our proposed random method in detail, how chooses locations of pixel in randomly , how to choose a random bit to hide information in the chosen pixel, how it different from other approaches, how applying information hiding criteria on the proposed project, and attempts to test out in code, and

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Publication Date
Fri Oct 19 2018
Journal Name
Journal Of Economics And Administrative Sciences
"The Effect of Organizational Power Top Management Resources in Building Core Competencies: Analytical Research
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The problem of the current research as the Iraqi Drilling Company suffers from the many challenges facing its work as a result of the current conditions in Iraq and the subsequent changes in the policies of the State Which left an impact on its activities and objectives, which created pressure on the importance of an organizational power capable of diagnosing the core competencies and development and maintain them to contribute to the raising and success in the performance of the company. The researchers adopted the method of analytical research and adopted the questionnaire as a main tool in the collection of research data and information . It was distributed to a community of (140) individuals from the low mana

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Publication Date
Mon Jan 01 2018
Journal Name
Aip Conference Proceedings
Fabricated and investigated the structure and super conductivity properties of Bi2Sr2Can-1CunO2n+4+δ compound
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Publication Date
Thu Mar 31 2022
Journal Name
Journal Of The College Of Education For Women
The Impact of a Counseling Program with a Cognitive Reconstruction Method on the Development of the Psychological Hardness among Middle School Students
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The current research aims to determine the impact of the cognitive reconstruction program on the development of psychological hardness among middle school students through the experimental verification of three hypotheses. The research sample consisted of (16) out of (450) students selected from Ibn Rushud preparatory school- Al-Rusafa 2. These participants have been randomly distributed into two equal groups. The researcher has used the method of cognitive reconstruction with the experimental group, whereas with the controlling group, he used nothing. The researcher has further used the scale of psychological hardness of Kobassa with the participants; the scale has been built in a way that suits the sample of the study, which consisted

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Publication Date
Wed Jan 01 2025
Journal Name
Journal Of Renewable Materials
Boosting Structural and Dielectric Properties of Polyvinyl Alcohol/Starch/Carboxymethyl Cellulose Films with Iron-Doped Carbon Quantum Dots for Advanced Applications
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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Comparing Study of The Stability and spectral properties vibrations for some Tellurium (IV) compounds containing cycloctadienyl group by Quantum Mechanical Calculations
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Density Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.

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Publication Date
Fri Dec 30 2022
Journal Name
Journal Of The College Of Education For Women
Constructing Imminent Carcinogenic Attack in English and Arabic Scientific Discourse: A Corpus-Based Contrastive Study
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Cancer is one of the critical health concerns. Health authorities around the world have devoted great attention to cancer and cancer causing factors to achieve control against the increasing rate of cancer. Carcinogens are the most salient factors that are accused of causing a considerable rate of cancer cases. Scientists, in different fields of knowledge, keep warning people of the imminent attack of carcinogens which are surrounding people in the environment and may launch their attack at any moment. The present paper aims to investigate the linguistic construction of the imminent carcinogen attack in English and Arabic scientific discourse. Such an investigation contributes to enhancing the scientists’ awareness of the linguistic co

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